%PDF-
%PDF-
Mini Shell
Mini Shell
<?php
/**
* Handler for DjVu images.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
* @ingroup Media
*/
/**
* Handler for DjVu images
*
* @ingroup Media
*/
class DjVuHandler extends ImageHandler {
const EXPENSIVE_SIZE_LIMIT = 10485760; // 10MiB
/**
* @return bool
*/
function isEnabled() {
global $wgDjvuRenderer, $wgDjvuDump, $wgDjvuToXML;
if ( !$wgDjvuRenderer || ( !$wgDjvuDump && !$wgDjvuToXML ) ) {
wfDebug( "DjVu is disabled, please set \$wgDjvuRenderer and \$wgDjvuDump\n" );
return false;
} else {
return true;
}
}
/**
* @param File $file
* @return bool
*/
public function mustRender( $file ) {
return true;
}
/**
* True if creating thumbnails from the file is large or otherwise resource-intensive.
* @param File $file
* @return bool
*/
public function isExpensiveToThumbnail( $file ) {
return $file->getSize() > static::EXPENSIVE_SIZE_LIMIT;
}
/**
* @param File $file
* @return bool
*/
public function isMultiPage( $file ) {
return true;
}
/**
* @return array
*/
public function getParamMap() {
return [
'img_width' => 'width',
'img_page' => 'page',
];
}
/**
* @param string $name
* @param mixed $value
* @return bool
*/
public function validateParam( $name, $value ) {
if ( $name === 'page' && trim( $value ) !== (string)intval( $value ) ) {
// Extra junk on the end of page, probably actually a caption
// e.g. [[File:Foo.djvu|thumb|Page 3 of the document shows foo]]
return false;
}
if ( in_array( $name, [ 'width', 'height', 'page' ] ) ) {
if ( $value <= 0 ) {
return false;
} else {
return true;
}
} else {
return false;
}
}
/**
* @param array $params
* @return bool|string
*/
public function makeParamString( $params ) {
$page = $params['page'] ?? 1;
if ( !isset( $params['width'] ) ) {
return false;
}
return "page{$page}-{$params['width']}px";
}
/**
* @param string $str
* @return array|bool
*/
public function parseParamString( $str ) {
$m = false;
if ( preg_match( '/^page(\d+)-(\d+)px$/', $str, $m ) ) {
return [ 'width' => $m[2], 'page' => $m[1] ];
} else {
return false;
}
}
/**
* @param array $params
* @return array
*/
function getScriptParams( $params ) {
return [
'width' => $params['width'],
'page' => $params['page'],
];
}
/**
* @param File $image
* @param string $dstPath
* @param string $dstUrl
* @param array $params
* @param int $flags
* @return MediaTransformError|ThumbnailImage|TransformParameterError
*/
function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
global $wgDjvuRenderer, $wgDjvuPostProcessor;
if ( !$this->normaliseParams( $image, $params ) ) {
return new TransformParameterError( $params );
}
$width = $params['width'];
$height = $params['height'];
$page = $params['page'];
if ( $flags & self::TRANSFORM_LATER ) {
$params = [
'width' => $width,
'height' => $height,
'page' => $page
];
return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
}
if ( !wfMkdirParents( dirname( $dstPath ), null, __METHOD__ ) ) {
return new MediaTransformError(
'thumbnail_error',
$width,
$height,
wfMessage( 'thumbnail_dest_directory' )
);
}
// Get local copy source for shell scripts
// Thumbnail extraction is very inefficient for large files.
// Provide a way to pool count limit the number of downloaders.
if ( $image->getSize() >= 1e7 ) { // 10MB
$work = new PoolCounterWorkViaCallback( 'GetLocalFileCopy', sha1( $image->getName() ),
[
'doWork' => function () use ( $image ) {
return $image->getLocalRefPath();
}
]
);
$srcPath = $work->execute();
} else {
$srcPath = $image->getLocalRefPath();
}
if ( $srcPath === false ) { // Failed to get local copy
wfDebugLog( 'thumbnail',
sprintf( 'Thumbnail failed on %s: could not get local copy of "%s"',
wfHostname(), $image->getName() ) );
return new MediaTransformError( 'thumbnail_error',
$params['width'], $params['height'],
wfMessage( 'filemissing' )
);
}
# Use a subshell (brackets) to aggregate stderr from both pipeline commands
# before redirecting it to the overall stdout. This works in both Linux and Windows XP.
$cmd = '(' . wfEscapeShellArg(
$wgDjvuRenderer,
"-format=ppm",
"-page={$page}",
"-size={$params['physicalWidth']}x{$params['physicalHeight']}",
$srcPath );
if ( $wgDjvuPostProcessor ) {
$cmd .= " | {$wgDjvuPostProcessor}";
}
$cmd .= ' > ' . wfEscapeShellArg( $dstPath ) . ') 2>&1';
wfDebug( __METHOD__ . ": $cmd\n" );
$retval = '';
$err = wfShellExec( $cmd, $retval );
$removed = $this->removeBadFile( $dstPath, $retval );
if ( $retval != 0 || $removed ) {
$this->logErrorForExternalProcess( $retval, $err, $cmd );
return new MediaTransformError( 'thumbnail_error', $width, $height, $err );
} else {
$params = [
'width' => $width,
'height' => $height,
'page' => $page
];
return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
}
}
/**
* Cache an instance of DjVuImage in an Image object, return that instance
*
* @param File|FSFile $image
* @param string $path
* @return DjVuImage
*/
function getDjVuImage( $image, $path ) {
if ( !$image ) {
$deja = new DjVuImage( $path );
} elseif ( !isset( $image->dejaImage ) ) {
$deja = $image->dejaImage = new DjVuImage( $path );
} else {
$deja = $image->dejaImage;
}
return $deja;
}
/**
* Get metadata, unserializing it if necessary.
*
* @param File $file The DjVu file in question
* @return string XML metadata as a string.
* @throws MWException
*/
private function getUnserializedMetadata( File $file ) {
$metadata = $file->getMetadata();
if ( substr( $metadata, 0, 3 ) === '<?xml' ) {
// Old style. Not serialized but instead just a raw string of XML.
return $metadata;
}
Wikimedia\suppressWarnings();
$unser = unserialize( $metadata );
Wikimedia\restoreWarnings();
if ( is_array( $unser ) ) {
if ( isset( $unser['error'] ) ) {
return false;
} elseif ( isset( $unser['xml'] ) ) {
return $unser['xml'];
} else {
// Should never ever reach here.
throw new MWException( "Error unserializing DjVu metadata." );
}
}
// unserialize failed. Guess it wasn't really serialized after all,
return $metadata;
}
/**
* Cache a document tree for the DjVu XML metadata
* @param File $image
* @param bool $gettext DOCUMENT (Default: false)
* @return bool|SimpleXMLElement
*/
public function getMetaTree( $image, $gettext = false ) {
if ( $gettext && isset( $image->djvuTextTree ) ) {
return $image->djvuTextTree;
}
if ( !$gettext && isset( $image->dejaMetaTree ) ) {
return $image->dejaMetaTree;
}
$metadata = $this->getUnserializedMetadata( $image );
if ( !$this->isMetadataValid( $image, $metadata ) ) {
wfDebug( "DjVu XML metadata is invalid or missing, should have been fixed in upgradeRow\n" );
return false;
}
$trees = $this->extractTreesFromMetadata( $metadata );
$image->djvuTextTree = $trees['TextTree'];
$image->dejaMetaTree = $trees['MetaTree'];
if ( $gettext ) {
return $image->djvuTextTree;
} else {
return $image->dejaMetaTree;
}
}
/**
* Extracts metadata and text trees from metadata XML in string form
* @param string $metadata XML metadata as a string
* @return array
*/
protected function extractTreesFromMetadata( $metadata ) {
Wikimedia\suppressWarnings();
try {
// Set to false rather than null to avoid further attempts
$metaTree = false;
$textTree = false;
$tree = new SimpleXMLElement( $metadata, LIBXML_PARSEHUGE );
if ( $tree->getName() == 'mw-djvu' ) {
/** @var SimpleXMLElement $b */
foreach ( $tree->children() as $b ) {
if ( $b->getName() == 'DjVuTxt' ) {
// @todo File::djvuTextTree and File::dejaMetaTree are declared
// dynamically. Add a public File::$data to facilitate this?
$textTree = $b;
} elseif ( $b->getName() == 'DjVuXML' ) {
$metaTree = $b;
}
}
} else {
$metaTree = $tree;
}
} catch ( Exception $e ) {
wfDebug( "Bogus multipage XML metadata\n" );
}
Wikimedia\restoreWarnings();
return [ 'MetaTree' => $metaTree, 'TextTree' => $textTree ];
}
function getImageSize( $image, $path ) {
return $this->getDjVuImage( $image, $path )->getImageSize();
}
function getThumbType( $ext, $mime, $params = null ) {
global $wgDjvuOutputExtension;
static $mime;
if ( !isset( $mime ) ) {
$magic = MediaWiki\MediaWikiServices::getInstance()->getMimeAnalyzer();
$mime = $magic->guessTypesForExtension( $wgDjvuOutputExtension );
}
return [ $wgDjvuOutputExtension, $mime ];
}
function getMetadata( $image, $path ) {
wfDebug( "Getting DjVu metadata for $path\n" );
$xml = $this->getDjVuImage( $image, $path )->retrieveMetaData();
if ( $xml === false ) {
// Special value so that we don't repetitively try and decode a broken file.
return serialize( [ 'error' => 'Error extracting metadata' ] );
} else {
return serialize( [ 'xml' => $xml ] );
}
}
function getMetadataType( $image ) {
return 'djvuxml';
}
function isMetadataValid( $image, $metadata ) {
return !empty( $metadata ) && $metadata != serialize( [] );
}
function pageCount( File $image ) {
$info = $this->getDimensionInfo( $image );
return $info ? $info['pageCount'] : false;
}
function getPageDimensions( File $image, $page ) {
$index = $page - 1; // MW starts pages at 1
$info = $this->getDimensionInfo( $image );
if ( $info && isset( $info['dimensionsByPage'][$index] ) ) {
return $info['dimensionsByPage'][$index];
}
return false;
}
protected function getDimensionInfo( File $file ) {
$cache = ObjectCache::getMainWANInstance();
return $cache->getWithSetCallback(
$cache->makeKey( 'file-djvu', 'dimensions', $file->getSha1() ),
$cache::TTL_INDEFINITE,
function () use ( $file ) {
$tree = $this->getMetaTree( $file );
return $this->getDimensionInfoFromMetaTree( $tree );
},
[ 'pcTTL' => $cache::TTL_INDEFINITE ]
);
}
/**
* Given an XML metadata tree, returns dimension information about the document
* @param bool|SimpleXMLElement $metatree The file's XML metadata tree
* @return bool|array
*/
protected function getDimensionInfoFromMetaTree( $metatree ) {
if ( !$metatree ) {
return false;
}
$dimsByPage = [];
$count = count( $metatree->xpath( '//OBJECT' ) );
for ( $i = 0; $i < $count; $i++ ) {
$o = $metatree->BODY[0]->OBJECT[$i];
if ( $o ) {
$dimsByPage[$i] = [
'width' => (int)$o['width'],
'height' => (int)$o['height'],
];
} else {
$dimsByPage[$i] = false;
}
}
return [ 'pageCount' => $count, 'dimensionsByPage' => $dimsByPage ];
}
/**
* @param File $image
* @param int $page Page number to get information for
* @return bool|string Page text or false when no text found.
*/
function getPageText( File $image, $page ) {
$tree = $this->getMetaTree( $image, true );
if ( !$tree ) {
return false;
}
$o = $tree->BODY[0]->PAGE[$page - 1];
if ( $o ) {
$txt = $o['value'];
return $txt;
} else {
return false;
}
}
}
Zerion Mini Shell 1.0